Mitochondrial Calcium Increase Induced by RyR1 and IP3R Channel Activation After Membrane Depolarization Regulates Skeletal Muscle Metabolism.

ABSTRACT: Aim: We hypothesize that both type-1 ryanodine receptor (RyR1) and IP₃-receptor (IP₃R) calcium channels are necessary for the mitochondrial Ca²⁺ increase caused by membrane depolarization induced by potassium (or by electrical stimulation) of single skeletal muscle fibers; this calcium increase would couple muscle fiber excitation to an increase in metabolic output from mitochondria (excitation-metabolism coupling). Methods: Mitochondria matrix and cytoplasmic Ca²⁺ levels were evaluated in fibers isolated from flexor digitorium brevis muscle using plasmids for the expression of a mitochondrial Ca²⁺ sensor (CEPIA3mt) or a cytoplasmic Ca²⁺ sensor (RCaMP). The role of intracellular Ca²⁺ ch

SUBMITTER: Diaz-Vegas AR 

PROVIDER: S-EPMC6026899 | biostudies-literature | 2018

REPOSITORIES: biostudies-literature